Ubuntu is VERY easy to set up, especially the new 7.10 version. It automatically sets up a bootloader so you can boot into Ubuntu or Windows and the 7.10 version automatically installs Compiz Fusion (which is similar to Beryl, it's a 3d window effects system) and has the Restricted Driver Manager to make video card drivers, network drivers, etc easy to install.
It's really easy. You first get a CD by ordering it from the ShipIt (they'll send you free CD's) program, or download an ISO and burn it. Both at
Ubuntu Home Page | Ubuntu. Then, reboot your PC and boot into that CD. It will have a menu, just run Ubuntu normally (first option). It will load into a desktop all ready and running. You can try out the system using the Live CD and then go to System -> Administration -> Partition Editor to set up partitions. GParted (the partition editor) can resize, move, delete, or create Windows and Linux partitions. Free up some space on the desired drive (but leave it empty, the installer will format the space) and select Apply. Now run the Installer, follow the instructions, and when it asks to migrate your data, I'd recommend saying No. I had problems with the migration assistant, but that was when it was in beta. It will automatically format the partition (select use largest free space on whatever drive when it asks where to install to) and copy the files, then set up the GRUB bootloader. Then you can restart your PC and you'll have a screen that asks what OS to run, select Linux, and have fun.
When you first enter Ubuntu, it will probably say there are restricted drivers for your card (assuming you have Radeon X1k or higher or nVidia GeForce graphics). Select the check box and it will download and install drivers (you need Ethernet for this, as most WiFi cards also need to download drivers from the Internet). Repeat for wireless cards if you have them. Then, to enable Compiz, right click, go to Change Desktop Background, click Effects, and select one of the options. If you want fancier effects, you can install them using Synaptic (go to System -> Admin. -> Synaptic Package Manager). Then do a search for "compiz" and install the compiz fusion plugins, compiz gtk frontend gui, and emerald packages. After applying, downloading, and installing the packages, you can now tweak Compiz to your likings and have really cool looking effects (which work great on graphics cards as old as a GeForce4 MX420/64MB RAM).
And the difference between Ubuntu and Beryl is this. Ubuntu is a distro (distribution). It is a whole Linux-based operating system comprised of the Linux kernel, the GNOME window manager, the XOrg X server, and a whole bunch of open-source programs. Beryl is a window manager/window decorator package. It provides 3d-accelerated decoration of windows and other GUI elements. It can be compared to Windows Vista's Aero. Beryl has since merged with Compiz, and the result is Compiz Fusion, a very nice window manager/decorator included in the latest Ubuntu release.
Multiple boot 
Linear Mode
